class_docstr: Dummy Problem for running the policy.
code: def hparams(self, defaults, model_hparams):
      # Update the env's hparams.
      self._ttt_env.hparams(defaults, model_hparams)
      # Do these belong here?
      defaults.modality.update(
          {
              "input_action": modalities.ModalityType.SYMBOL_WEIGHTS_ALL,
              "input_reward": modalities.ModalityType.SYMBOL_WEIGHTS_ALL,
              "target_action": modalities.ModalityType.SYMBOL_WEIGHTS_ALL,
              "target_reward": modalities.ModalityType.SYMBOL_WEIGHTS_ALL,
              "target_policy": modalities.ModalityType.IDENTITY,
              "target_value": modalities.ModalityType.IDENTITY,
          }
      )
      defaults.vocab_size.update(
          {
              "input_action": self.num_actions,
              "input_reward": 3,  # -1, 0, +1 ?
              "target_action": self.num_actions,
              "target_reward": 3,  # -1, 0, +1 ?
              "target_policy": None,
              "target_value": None,
          }
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import gym
  from gym import spaces
  from gym.utils import seeding
  import numpy
  from tensor2tensor.data_generators import problem
  from tensor2tensor.layers import modalities
  from tensor2tensor.rl import gym_utils
label_desc: Use image node_id 2 for calling the DummyPolicyProblemTTT obj's underlying member method code with example usage: obj.hparams(defaults, model_hparams) without return types